Ralf’s GaN & SiC News (September 12, 2024)
Welcome to the latest edition of my newsletter on silicon carbide, gallium nitride, and other wide-bandgap semiconductor materials. If you want to get covered, please reach out to me via [email protected]
Gallium Nitride News
Infineon presents 300-mm power GaN technology
英飞凌 announced that it has developed the world’s first 300-mm power GaN-on-Si wafer technology. For this, the company used an integrated pilot line in the existing 300-mm silicon fab in Villach (Austria). The company said that it is leveraging well-established competence in the existing production of 300-mm silicon and 200-mm GaN. Infineon will further scale GaN capacity aligned with market needs.
Chip production on 300-mm wafers is technologically more advanced and significantly more efficient compared to 200-mm wafers since the bigger wafer diameter offers 2.3 times more chips per wafer. 300-mm GaN manufacturing might put Infineon in a position to shape the growing GaN market which is estimated to reach several billion US dollars by the end of the decade.
However, when asked how Infineon solved the problem of wafer warping, they remained vague. They said that this is one of their most important IP areas and its competence center for GaN epitaxy is said to have the best engineers with decades of experience in GaN epitaxy process development. One of the biggest challenges in the production of GaN is the growth of a homogeneous GaN layer on the Si substrate (epitaxy). The larger the wafer diameter, the greater this challenge becomes. For GaN on a 300-mm Si wafer, this stress is as high as four elephants (5 metric tons each) sitting on a 1-euro cent coin.
“The technological breakthrough will be an industry game-changer and enable us to unlock the full potential of gallium nitride. Nearly one year after the acquisition of GaN Systems, we are demonstrating again that we are determined to be a leader in the fast-growing GaN market. As a leader in power systems, Infineon is mastering all three relevant materials: silicon, silicon carbide, and gallium nitride,” said CEO Jochen Hanebeck .
Samsung invests in the GaN market with MOCVD from Aixtron
The Korean news outlet Alpha Biz reports that 三星电子 has made strides into the GaN foundry market through a small-scale investment in MOCVD equipment from AIXTRON SE at its Giheung plant in the second quarter. This facility is responsible for the mass production of 200-mm foundry products and also houses Samsung's existing facilities dedicated to GaN research and development.
This is in line with the announcement during the "Samsung Foundry Forum 2023" held in Silicon Valley last June. The company announced its plan to launch 200-mm GaN power semiconductor foundry services by 2025, targeting consumer electronics, data centers, and automotive markets.
However, the recent investment by Samsung Electronics is understood to involve the acquisition of only one or two units of Aixtron's latest MOCVD equipment. This cautious approach may be due to the company not yet securing a major customer and focusing its capital expenditures on areas like high-bandwidth memory (HBM). As a result, Samsung seems to be strategically pacing its investment in the GaN foundry sector.
Trustees pull the plug on insolvent BelGan
The trustees overseeing the insolvency procedure of the Flemish GaN foundry BelGaN have commenced the sale of the company’s assets. Even though five interested parties made a bid, none of them were sufficient to warrant further negotiations. “We’re pulling the plug. The highest bid isn’t even half of the liquidation value of 50 million euros,” said Ali Heerman , one of the trustees, in the newspaper De Tijd , as Bits&Chips report.
Gerard de Bourbon , representing the Finnish-Swedish consortium 7 Semiconductors , expressed frustration on a LinkedIn post after the trustees rejected his bid to acquire the factory. “Despite having the highest bid, the bankruptcy administrators believe they can get more for the equipment. This is a sad end to a strategic business essential to European security and de-risking the dependencies on Taiwan for wide-bandgap semiconductors. I only hope lawmakers pay attention to a critical issue and the gargantuan problems industry and society will face should China decide to invade Taiwan. The administrators failed to understand that the value of a fab is its people. Without them, it's just equipment. This is a complex business and requires specific competence. They should have brought the bidders interested in continuing the business after the first offer to the table for discussions, and jobs would have been spared.”
But why did this promising factory, aligned with global trends in semiconductors and energy-efficient tech, fail to attract a buyer? Peter H.J. Auwerx analyzed on LinkedIn why tech ventures like BelGan struggle to survive despite promising technologies. Here, is his summary:
Shin-Etsu Chemical to develop a QST substrate for 300-mm GaN
Shin-Etsu Chemical has created a 300-mm (12-inch) QST substrate, which is a substrate dedicated to GaN epitaxial growth, and recently started supplying samples. This large-diameter substrate enables GaN epitaxial growth without warping or cracks, which was unattainable on Si substrates, thus significantly reducing device costs. The company works on mass-producing 300-mm QST substrates which they have licensed from Qromis, Inc.
Since QST substrates have the same coefficient of thermal expansion as that of GaN, it is possible to constrain warping and cracks of the GaN epitaxial layer on the QST substrate of the SEMI standard thickness. This substrate material allows for high-quality and thick GaN epitaxial growth with a large diameter. Leveraging this feature, many customers are evaluating QST substrates and GaN on QST epitaxial substrates for power devices, high-frequency devices, and LEDs. Despite the challenging business environment, customers have entered the development phase toward practicality to address the recently increasing interest in power devices, including power supplies for data centers.
Yole webcast: GaN, from innovation to mass production
Last June, Ezgi Dogmus, PhD from Yole Group , along with David Haynes and Michelle Bourke from Lam Research , presented a webcast addressing these concerns. They were joined by Yann Lamy from CEA-Leti and Taha Ayari, PhD from Yole Group to further discuss the topic. Here are their key insights.
Since 2019, Power GaN devices have been firmly embraced by the consumer sector. It is expected to remain the main driver of growth in this market (CAGR23-29 projections of 41%), with significant contributions from data centers and automotive applications. 英飞凌 , 意法半导体 , ROHM, and Nexperia will not remain the only high-volume GaN transistor manufacturers for long. The power GaN ecosystem is evolving rapidly with coming entrants such as Mitsubishi Electric and 威世 , and notable acquisitions like Infineon-GaN Systems, STMicroelectronics- Exagan and 瑞萨电子 - Transphorm Inc.
Performance degradation of GaN transistors during manufacturing processes is a major concern. For commercial applications, a negative bias is necessary to turn the device from the on-state (D mode) to the off-state (E mode). Various structural approaches, such as recessed gate MISHEMT and p-GaN under gate HEMT, have been considered. However, the 2D electron gas (2DEG) layer is highly sensitive to damage during manufacturing. GaN active layers are subject to substrate state modification, lattice disorder introduction, and species trapping, all of which can reduce 2DEG density and impact overall transistor performance. To mitigate this, careful attention must be paid to the etching, passivation, and cleaning steps. This is, where Lam Research comes into play. This article dives into this, and the collaboration with CEA-Leti.
Experimental investigation of GaN-on-AlN/SiC transistors with regard to monolithic integration
The monolithic integration of the GaN-on-Si HEMTs is challenging since the back-gating effects caused by a common substrate degrade the device's performance. In this article, researchers from Technische Universit?t Berlin and Ferdinand-Braun-Institut, Leibniz-Institut für H?chstfrequenztechnik introduce novel GaN-on-AlN/SiC power HEMTs.
Compared with conventional GaN-on-Si HEMTs, the presented transistors show immunity to back-gating effects, thereby enabling monolithic integration of power devices without degradation of performance. Discrete power HEMTs are characterized systematically regarding both static and switching characteristics with a focus on the impact of the substrate potential. Furthermore, monolithic GaN-on-AlN/SiC half-bridges and monolithic GaN-on-AlN/SiC bidirectional switches are fabricated using the same device technology.
The switching characteristics of these monolithically integrated devices are also investigated for different substrate terminations. It is demonstrated that both discrete and monolithically integrated devices achieve stable and fast switching and show a satisfactory back-gating immunity.
Xiaomeng Geng, Nick Wieczorek, Mihaela Wolf, Carsten Kuring, Frank Brunner, Hans-Joachim Würfl, Oliver Hilt, Sibylle Dieckerhoff, "Experimental Investigation of GaN-on-AlN/SiC Transistors With Regard to Monolithic Integration," in IEEE Transactions on Power Electronics, vol. 39, no. 10, pp. 12615-12624, Oct. 2024, doi: 10.1109/TPEL.2024.3432327.
Job exchange
BelGaN’s R&D manager is open to work
As R&D manager of BelGaN , Dr. Arno Stockman is actively seeking new opportunities in the semiconductor industry, after several years of working at BelGaN and 安森美半导体 . With extensive experience in semiconductor device integration and reliability assessment, both in technical and managerial roles, he is eager to bring my skills to a dynamic team and contribute to cutting-edge innovations in the field.
Miscellaneous News
Lower-cost SiC and high-voltage GaN using engineered substrates
Engineered substrates could potentially decrease the overall device cost of SiC MOSFETs by reducing the amount of monocrystalline SiC per device, and can increase the maximum voltage of GaN HEMTs, presenting advantages for use in EV traction. This is the essence of an analysis from IDTechEx .
Furthermore, the wide availability will increase production volumes and reduce lead times, as epitaxial growth is slow, and engineered substrates can be mass-produced. For GaN, newer vertical devices will have greater power density, and for SiC, die areas will reduce, also increasing power density.
For SiC, this results in reduced costs, with monocrystalline SiC substrates taking up to 50% of a total device's cost and increased volume, with one monocrystalline SiC wafer than able to produce 10-50 substrates. It has also been shown that engineered substrates have a lower 'on resistance' over the substrate area, resulting in less heat generated per unit area and the potential for a greater number of chips produced per substrate.
While engineered SiC substrates show potential, it will still take a couple of years for them to be in mass production, and questions remain over the main form of commercialization for them. For example, companies could license out the bonding process, partner with foundries or device companies to produce substrates at scale, or loan out the necessary equipment. Design cycles and lead times in the automotive industry are notoriously long, spanning multiple years. In addition, high requirements and extensive testing are needed to qualify these processes to make devices for EVs.
IDTechEx is aware of only one company, Odyssey Semiconductor Technologies, Inc , that produces bulk GaN substrates for GaN devices. In May 2024, it was acquired by Power Integrations , but it remains to be seen whether GaN substrates can be manufactured reliably and cost-effectively.
With GaN substrates currently being prohibitively expensive, the next best thing is to manufacture something as similar as possible to GaN, which is what engineered substrates aim to do. Alternative substrates such as SiC and sapphire come with other drawbacks, therefore engineered substrates could be a key technology in enabling GaN to enter the EV power electronics market. However, IDTechEx is not aware of any current adoption plans from automotive OEMs or tier-one suppliers.
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To summarize, engineered substrates will open the path to vertical GaN devices and can make devices reliable, more cost-effective, scalable, and power-dense.
Webinar: MHz-Frequency High-Current Power MOSFET Technology for AI Data Centers
Modern-day GPUs have tens of billions of transistors. Better processor performance comes at the price of exponentially rising power demands, so high-performance processors for applications like artificial intelligence (AI) and machine learning (ML) demand continuously more power. Meanwhile, core voltages are declining with advanced processing nodes contributing to the growth of the peak currents of up to 2,000A. High-frequency and ultra-low R(DS(on)) power MOSFETs play a critical role in the high-efficiency ultra-compact Power Delivery Network (PDN) to power up the AI chips.
In this IEEE Power Electronics Society webinar, John Shen from 加拿大西蒙弗雷泽大学 will discuss various types of power MOSFETs in terms of R(DS(on)), gate charge, capacitance, and other performance parameters and their advantages and disadvantages in modern PDN converter designs, including vertical trench MOSFETs. LDMOS transistors, and GaN FETs.
Silicon Carbide News
Gate switching instability in SiC MOSFETs—Part II: Modeling
It has recently been observed that bipolar switching between accumulation and inversion can result in an unexpected threshold voltage drift in SiC MOSFETs. This phenomenon has been termed gate switching instability (GSI) and is characterized by power-law time exponents close to unity, significantly larger than what is typically observed for ordinary bias temperature instability (BTI) during static or unipolar switching stress.
Since the bias, frequency, and temperature dependence of GSI are the same as what is seen in charge pumping (CP) experiments, a team of researchers from Technische Universit?t Wien , Infineon Technologies, Johannes Kepler Universit?t Linz , and KAI stipulate that recombination events at the interface lead to recombination-enhanced defect reactions (REDRs), which can eventually lead to degradation.
Based on these observations, the researchers develop a comprehensive physical model for GSI, discuss its features, derive a closed-form analytical solution, and finally validate the model against detailed experimental data.
This is the second part of the research. The first part can be found here.
Tibor Grasser , Dr. Maximilian W. Feil , Dr. Katja Waschneck , Hans Reisinger, Judith Berens , Dominic Waldh?r, Aleksandr Vasilev, Michael Waltl , Thomas Aichinger , Michel Bockstedte, Wolfgang Gustin, and Gregor Pobegen , "Gate Switching Instability in Silicon Carbide MOSFETs—Part II: Modeling," in IEEE Transactions on Electron Devices, vol. 71, no. 7, pp. 4218-4226, July 2024, doi: 10.1109/TED.2024.3397629.
ROHM and UAES Sign a Long-Term Supply Agreement for SiC Power Devices
ROHM Co., Ltd. and United Automotive Electronic Systems Co., Ltd., ( UAES ), a leading Tier 1 automotive supplier in China, have recently entered into a long-term supply agreement for SiC power devices.
Since 2015, ROHM and UAES have been collaborating and carrying out detailed technical exchanges on automotive applications utilizing SiC power devices. This partnership deepened in 2020 with the establishment of the joint SiC technology laboratory at the UAES headquarters in Shanghai, China. And in 2021 ROHM’s advanced SiC power devices and peripheral components were highly evaluated by UAES, resulting in ROHM Semiconductor Europe being selected as a preferred supplier.
This long-term supply agreement ensures UAES sufficient access to SiC power devices to meet the growing demand for SiC-based inverter modules, which have been supplied to customers since November 2023. Going forward, both companies will deepen their collaboration, contributing to technological innovation in the automotive sector by accelerating the development of cutting-edge SiC power solutions for EVs.
“Choosing ROHM as our long-term supplier of SiC chips guarantees a stable supply for future mass production. We appreciate ROHM’s past efforts and look forward to building a long-term collaborative relationship, with this agreement serving as a new starting point,” said Guo Xiaolu, Deputy General Manager, UAES.
Friedrich-Alexander-Universit?t Nuremberg starts research partnership with Sanan
The Institute for Power Electronics (LEE) at FAU Erlangen-Nürnberg entered into a research partnership with Sanan Semiconductor , a vertically integrated SiC supplier with in-house development and manufacturing of SiC substrates, epitaxial wafers, Diode/MOEFET dies and packaged products.
“This partnership with one of Germany’s leading academic research institutes for SiC puts Sanan Semiconductor in a strong position”, says Mr. Tony chiang , CEO of Sanan Semiconductor. Dr. Ming-Che Kao, General Manager of Sanan Europe GmbH says, “Europe is a key market for us, and this partnership aims at strengthening our system innovation, to help to get the best performance of our semiconductors”.
“Compared to traditional Silicon-based technologies, SiC power semiconductors offer significant efficiency and power density improvements in various applications. Despite the increasing adoption of SiC in power electronic applications, several system-level barriers still inhibit the full potential of SiC. This collaboration is a step towards overcoming these barriers”, says Dr. Ajay Poonjal Pai , Head of WBG Innovation.
“We are pleased to be able to start our first long-term joint research project with Sanan! This strong partner will enable us to advance into new performance regions with innovative SiC devices” says Prof. Dr.-Ing. Martin Maerz , head of the Chair of Power Electronics at FAU.
Webinar – Using deep learning reconstruction for high through-put and high-resolution 3D analysis of packaged SiC wafers
The rapid growth of SiC devices in the power and automotive industries is driving the need for advanced techniques in semiconductor analysis. Join the IMAPS-UK webinar to gain insights into the unique combinations of Electron Beam Induced Current (EBIC) and Passive Voltage Contrast (PVC), and how these methods provide complementary data essential for thorough junction analysis.?
Dr. Andrew Elliott , Materials Research Lead - Business Development Product & Applications Specialist at ZEISS Group , will delve into a case study where commercially available SiC MOSFET devices were cross-sectioned with a Crossbeam FIB-SEM in preparation for characterization. PVC highlighted the electron affinity or work function of various implant regions of the surface, showing strong contrasts between p and n regions. In contrast, EBIC is an image of the beam current response to electric fields associated with the depletion zones of a p/n junction. Depletion zones were easily characterized in the EBIC data.
Wolfspeed unveils cutting-edge 2300-V SiC module
Wolfspeed unveiled a SiC module designed to transform the renewable energy, energy storage, and high-capacity fast-charging sectors through improved efficiency, durability, reliability, and scalability. The 2300-V baseplate-less power modules for 1500V DC Bus applications were developed and launched utilizing Wolfspeed’s state-of-the-art 200-mm silicon carbide wafers.
These modules can improve system efficiency while reducing the number of passive components. They offer 15% greater voltage headroom compared to similar SiC modules, improved dynamic performance with consistent temperature stability, and a substantial reduction in EMI filter size. Wolfspeed’s technology achieves a 77% reduction in switching losses over IGBTs and a 2-3x reduction in switching losses for SiC devices intended for 1500-V applications.
2300-V SiC modules will allow system designers to leverage lower-cost PCBs to cut manufacturing costs and significantly reduce development time compared to legacy bus bar solutions. Furthermore, these modules can enable the industry to adopt the two-level topology, resulting in simplified system design and reduced driver count compared to IGBT-based three-level configurations. The benefits of 2300-V modules support a building block approach to easily scale power tenfold, from kilowatts to megawatts.
Wolfspeed’s 2300 V modules will allow customers to further enhance the lifetime and durability of their systems. This is achieved through an optimized Failure in Time rate for continuous 1500 V DC operation and improved cosmic ray susceptibility compared to a 2000V design. When used in a two-level implementation, 2300 V modules reduce the amount of potential single points of failure across the system.
Wolfspeed also announced that it is partnering with EPC Power Corp , a premier North American utility-scale inverter manufacturer. EPC Power will be employing the Wolfspeed modules in utility-grade solar and energy storage systems, which offer a scalable high-power conversion system and high-performance controls and system redundancy.
Navitas qualifies Gen-3 Fast SiC to AEC-Q101
Navitas Semiconductor announced the release of a portfolio of third-generation automotive-qualified SiC MOSFETs in D2PAK-7L (TO-263-7) and TOLL surface-mount packages. Both 650-V and 1,200-V ranges are AEC-Q101-qualified in the traditional SMT D2PAK-7L (TO-263-7) package. All parts of the series are released and available immediately for purchase.
Gen-3 Fast MOSFETs support increased power density in EV applications such as AC compressors, cabin heaters, DC-DC converters, and onboard chargers (OBCs). Navitas’ dedicated EV Design Center has demonstrated leading-edge OBC system solutions up to 22 kW with 3.5 kW/liter power density, and over 95.5% efficiency.
400 V-rated EV battery architectures are served by the new 650 V Gen-3 Fast MOSFETs featuring R(DS(ON))-ratings from 20 to 55 mΩ. The 1,200 V ranges from 18 to 135 mΩ and is optimized for 800-V systems.
Common-leg coupled inductor configuration in a three-level interleaved DC-DC medium voltage SiC-based converter
A team of researchers from Politechnika Bia?ostocka , Faculty of Electrical Engineering, Warsaw University of Technology , and MARKEL Sp. z o.o. proposes and investigates an alternative coupled inductor configuration in a three-level interleaved DC-DC converter. The new common-leg coupled inductor structure is introduced, and possible modulation methods are studied and theoretically analyzed, focusing on the impact on current ripples, power losses, and common-mode noise.
The concept is validated using an MV-rated, SiC-based bidirectional converter dedicated to battery storage application in a bipolar EV charging station, tested up to 1 kV and 10 kW. Furthermore, the comparative study shows that the suggested method exhibits a smaller volume when compared to the conventional approach with several single inductors, comparable performance but with a more straightforward inductor design than the tapped inductor solution and full section current controllability, unlike the single-inductor option. Finally, using the proposed technique, common-mode noise can be entirely limited, allowing the minimization of excess filtering.
Overall, the proposed inductor configuration can be effectively and competitively used in modern SiC-based three-level DC-DC converters.
Micha? Harasimczuk , Rafa? Kopacz , Rafa? Mi?kiewicz , Rados?aw Sobieski and Jacek Rabkowski , "Common-Leg Coupled Inductor Configuration in a Three-Level Interleaved DC–DC Medium Voltage SiC-Based Converter," in IEEE Transactions on Power Electronics, vol. 39, no. 8, pp. 9694-9704, Aug. 2024, doi: 10.1109/TPEL.2024.3396293.
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2 个月https://www.techzine.eu/blogs/infrastructure/124303/belgans-tempestuous-story-is-a-lesson-for-all-of-europe-possible-acquirer-bankrupt-chip-factory/
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2 个月Amazing read! There is a whole new world of possibilities beyond the basic Silicon, and we are just getting started.